Light curable materials are widely used in dentistry for the restoration of teeth. Such materials typically can be made to provide optical characteristics that resemble those of natural teeth, which makes those materials a favored alternative to unpleasant looking amalgam materials, for example.
Light-curable materials often include a polymerizable matrix material and filler materials including colorants, and may initially be generally soft or flowable so that they can be applied in a desired location and shape. For example, for restoration of a tooth the dental material may be filled into a tooth cavity and shaped so that the restored tooth resembles a natural tooth. Once the desired shape has been formed, the material may be cured by exposing it to light of a desired wavelength. The light typically activates photoinitiators in the dental material that cause the matrix material to polymerize.
The use of dental materials that are curable by blue light of a wavelength of between about 450 and 500 nm has become common in dentistry. Accordingly, light-emitting devices used for curing such dental materials typically emit light at such wavelengths. Such light-emitting device, for example, is available from 3M ESPE, Germany, under the trade designation Elipar™ Freelight 2 LED Curing Light.
Typically devices of the prior art have a time cut-off function that switches off the light after a certain period of time. Such devices also typically provide the possibility to set the cut-off time to certain values. However, it is still desirable to provide a device that allows easy adjustment of variables for appropriately curing dental materials in different situations. For example, over-hardening the material due to exposure to light at high intensity or for too long a duration should be avoided.